This invention relates in general to the production of useful products from biomass, and in particular to the energy densification of biomass-derived organic acids to produce products suitable for high energy density fuels.
World oil production is forecasted to peak within the next five years, which implies it is likely that the price of oil will increase significantly in the future. This is also evidenced by the fact that the price of oil was back to about $80/bbl at the end of 2009 after the worst economic recession since World War II. Furthermore, the combustion of fossil fuels is considered to be the major factor responsible for trends in global climate change, equaling about 82% of net green house gas emissions. In order to address these problems, there is a pressing need for the development of renewable fuels and energy derived from biomass, wind, geothermal heat and solar radiation in order to meet future economic and environmental requirements. Among these renewable resources, biomass is considered to be the only sustainable and carbon-neutral source for the production of liquid fuels. The US has the potential to sustainably produce biomass which can replace more than one-third of the 2004 US petroleum consumption.
Levulinic acid has been identified as one of the top value added, biomass-derived chemicals by the U.S. Department of Energy, and it can be produced from cellulose-containing biomass in high yields using the “Biofine” process. Levulinic acid esters such as ethyl levulinate have low energy content (26 MJ kg-1) compared to petroleum based fuels (46 MJ kg-1). While this relatively low energy density might be acceptable for ground transportation fuels it is unacceptable for aviation fuels. The energy density of the fuel impacts both the range and the carrying capacity of the aircraft. Therefore, it would be desirable to provide a process for the energy densification of biomass-derived levulinic acid and other organic acids.